The preparation and use of 2-amino-5-halo-6-alkyl-4-pyrimidinols as antiviral agents is known (U.S. Pat. No. 3,956,302, and Nicols, Weed and Underwood, Antimicrobial Agents, Chemo. Ther. 9 433, 1976). Preparation of 2-amino-5-bromo-6-phenyl-4-pyrimidinol (V, where X.sub.3 is Br and X.sub.1 is phenyl) has been reported (Brown and Stevens, JCS Perkin I, 1023, 1975) but no utility has been described for this material. Snell, Elias and Freeman in Great Britain Patent Number 1,223,686 (1967) disclose a variety of 5,6-disubstituted 2-amino-4-pyrimidinols, such as 2-dimethylamino-5-bromo-6-methyl-4-pyrimidinol. Various 5-unsubstituted 2-amino-6-arylpyrimidinols are known (e.g., Shirahawa, Yakugaku Zasshi 50, 1562, 1960, CA 55, 10651b), Kulkarui et al., J. Sci., Ind. Res. Indil, 19C, 6, 1960, and U.S. Pat. No. 2,776,283. Diuretics and cardioregulatory properties are described for various 2-amino and 2-substituted amino-5-aminomethyl and 5-aryl-6-aryl-4-pyrimidinols (U.S. Pat. Nos. 2,704,285, 2,723,777 and 2,776,283).
Related compounds wherein X is hydrogen have been described in copending U.S. application Ser. No. 022,205, filed Mar. 19, 1979, and are useful as antiviral and interferon inducing agents, or the Belgian equivalent thereof, Belgian Pat. No. 882,315.